Several types of charged substituted starches are commercially available and are currently used in paper-making and water treatment applications. Cationic starches are traditionally used on the wet end of paper manufacturing to increase wet strength and bind anionic “trash” in the wood pulp. Anionic and amphoteric starches are also used in paper formulations and at the size press of paper-making to improve finish and dry strength Amphoteric starches contain both cationic and anionic substituents. Charged starches are also used as flocculants in water treatment plants to remove contaminants. The cationic groups on charged starches are commonly quaternary amines and the anionic substituents are usually carboxylate or phosphate groups.
Some charged cellulose derivatives are also known. Carboxymethyl cellulose, an anionic cellulose derivative, is the most commonly used cellulose ether. It is mainly used as a thickener, but it is also used as an emulsion stabilizer, and textile warp sizing.